1. Field of the Invention
The present invention relates in general to V-type engines for automobiles, etc. and more particularly to a V-type engine lubrication system.
2. Description of the Prior Art
In a V-type engine lubrication system, its oil passage arrangement tends to become complicated or its associated engine tends to become large-sized due to the necessity of distributing lubricating oil to the left and right banks.
An example of this kind of lubrication system is disclosed in Japanese Utility Model Provisional Publication No. 61-18167 and is also shown in FIG. 6. In the FIG. 6 a cylinder block 81 is formed with an oil passage 82 extending across one of the banks for conducting lubricating oil to a main gallery (not shown) located between the banks.
An oil pump 83 is installed on a front casing 88 and adapted to be driven by an engine crankshaft by way of a pulley and belt.
Lubricating oil is drawn from a sump by the oil pump 83 and delivered through a pipe 84 on the side of the cylinder block 81 to oil filters 85, from which it is delivered through a pipe 86 and an oil cooler 87 to the oil passage 82.
In the lubrication system, cylinders in the left bank as viewed from the front end of the engine are offset a predetermined distance rearwardly from cylinders in the right bank, and the oil passage 82 is formed in an integral wall portion of the left bank, which wall portion results from the above offsetting.
In the meantime, terms "rearwardly" and "forwardly", "rear" and "front" are herein used with respect to a rear end and front end of an engine where a flywheel and cooling fan are respectively provided.
A problem of the lubrication system is that the oil passage 82 for providing communication between the main gallery and the oil pump 83 cannot be sufficiently large in diameter or bore since the amount of offsetting of the cylinders in the left bank cannot be sufficiently large due to design restrictions in the overall length, weight, etc. of the engine, resulting in that the pressure loss in the oil passage 82 is liable to become large and therefore making it impossible to attain efficient lubrication.
Another problem is that the pipes 84, 86 for providing communication between the oil passage 82 and the oil pump 83 by way of the oil filters 85 are lengthy and complicated in shape due to the necessity of arranging the oil pump 83 in such a way as to project forwardly from the front casing 88.